A conventional bicycle hub assembly is located at the center of the bicycle wheels and spokes are connected between the hub assembly and the rim of the wheel. For the front wheel hub assembly, the front fork can be connected to the flanges of the front wheel hub assembly. For the rear wheel hub assembly, the sprockets of derailleur system can be connected to the rear wheel hub assembly.
FIG. 10 shows a conventional bicycle hub assembly 80 which includes an axle with two circular flanges 81 on two ends thereof and spokes 82 are connected to the two flanges 81. It is noted that the flanges 81 protrude radially outward from the axle and the protruding flanges 81 do not meet the aerodynamic requirement.
When the wheels rotate, side wind is generated due to the rotation and the flanges 81 cause turbulence which increases resistance and affects the speed of the bicycle. Besides, because the spokes 82 are connected to the flanges and the head for fixing the spokes 82 to the flanges 81 protrude out from outside surface of the flanges 81, the heads make the shape of the flanges 81 to be complicated and cause noise and resistance.
The present invention intends to provide a bicycle hub assembly which includes a smooth and aero-dynamic outer profile to guide wind away from the hub and reduce turbulence.